THE ADIRONDACK GRAPHITE DEPOSITS I ,} I 



The equipment of the Hooper mill at the time of visit is verj 

 similar to that of the Make Graphite Company. Crushing, stamping, 

 huddling, screening and drying arc the essential steps in the process. 

 Further improvement is being made, the details of which are not 



made public. 



The dry process. Only three mills, so far as the writer knows, 

 have operated with the dry method: the Lakeside mine at Hague, 

 the Crown Point Graphite Company, and the Rowland plant. These 

 have been abandoned and little direct information is available. In 

 the Rowland mill a Newaygo separator, manufactured by the 

 Newaygo Portland Cement Company, was experimented with, but 

 apparent!} without success. 



The finishing of graphite. In the early days of the industry, 

 the mines in the vicinity of Crown Point sent their concentrates to 

 a finishing mill located at Crown Point Center. Power was secured 

 from Putnam creek. As it has long been closed, details of the 

 processes used there are unavailable. 



The American Graphite Company maintains its refining mill at 

 Ticonderoga ; the Flake Graphite Company and the Graphite Pro- 

 ducts Corporation finish their products on their own properties. 



The machine that is most generally used in the final treatment of 

 the graphite concentrates is the Hooper pneumatic concentrator, 

 a brief account of which is here given. 1 



In essence it consists of an inclined frame over which is stretched 

 a broadcloth screen, up through which a continuous series of air 

 pulsations are delivered by a device located below. Two sets of 

 strips are arranged over the cloth screen, the lower group of which 

 is inclined toward one side, while the upper set is inclined in the 

 opposite direction. ". ... and when (concentrates) composed of 

 particles of different gravities are fed upon the (screen) the pul- 

 sations through the broadcloth . . . cause the heavier mineral 

 particles to be thrown (settle) to the bottom . . . and are 

 thus guided . . . toward the tailing side of the (concen- 

 trator)," 2 while the clean graphite is guided by the upper set of 

 strips to the opposite, or concentrating side, thus bringing about a 

 separation of the gangue and the ore. 



1 For a full description, see Richards, " Ore Dressing," p. 820, and Canadian 

 Min. Tour., 30:271-72, 1909. 



2 Ibid. 



